Booth began his career with Wells Fargo Bank in San Francisco after earning his MBA in 1971. He returned to Chicago in 1975 to join Becker Securities, Inc., eventually becoming vice president of investment counseling.

Sinquefield spent nine years at American National Bank & Trust Company after receiving his MBA in 1972, rising to chief investment officer, executive vice president, and chairman of the trust committee. Each left his respective position to form Dimensional Fund Advisors, Inc., in 1981.

Using a strategy based on rigorous academic research, Dimensional bucked the notion that a Wall Street stock picker can consistently beat the market with enough knowledge and research. By 1999, overcoming 20 years of Wall Street skepticism, Dimensional was the ninth largest institutional fund manager in the United States, specializing in brokerage, securities, and investments. It was the first firm to introduce a small business stock fund that was fully indexed, a practice that has since become the industry standard.